Analysis of multilayer thermodesorption spectra

A277 1

Surface Science 186 (1987) 1-14 North-Holland, Amsterdam

ANALYSIS

OF MULTILAYER

L.A. LAXHUBER

Technical University Munich, Fed. Rep. of Germany Received

19 January

THERMODESORPTION

SPECTRA

and H. MOHWALD Physics-Department

1987; accepted

E22 (Biophysics),

for publication

19 February

D-8046 Garching 1987

A model is presented to analyze thermodesorption spectra of multilayers, taking into account the individual characteristic of each monolayer composing the system. The applicability of the model to study the thermostability of Langmuir-Blodgett films with varying film thickness is demonstrated. Thus information on desorption of the organic film as regards binding energy, frequency factor and reaction order can be derived.

15

Surface Science 186 (1987) 15-25 North-Holland, Amsterdam

Li - FORMATION

J.J.C. GEERLINGS, FOM-Institute for Atomic The Netherlands

AT LOW NORMAL

VELOCITIES

R. RODINK, J. LOS and Molecular

Physics, Kruislaan

407, 1098 SJ Amsterdam,

J.P. GAUYACQ Laboratoire des Collisions Atomrques 91405 Orsay Cedex, France

et Moltkulaires

*, B&iment

Received

for publication

19 March

21 January

1987; accepted

351, UniversitP Paris-Sud 1987

Li- formation is studied by scattering a Li+ beam from a cesium covered tungsten (110) surface. The energy of the primary particles is varied between 100 and 1000 eV. It is found that the probability for Li- formation is a function of the velocity component of the scattered particles normal to the surface only. In the normal velocity range between 5 X lo3 and 2 x lo4 m/s the formation probability is exponentially dependent on the reciprocal normal velocity. The experimental results are explained by a simple semi-classical model.